Vaccine against Potomac horse fever and method of preparation therefore

Abstract

A vaccine against Potomac Horse Fever comprises a deactivated E. risticii as the active agent. The agent may be obtained through inoculation of a cell culture, followed through deactivation by exposure to b-propiolactone. The deactivated E. risticii is subsequently isolated and suspended in a pharmaceutically acceptable carrier. Considerable protection against infection is conferred. An assay is also prepared.

What is claimed as new and desired to be secured by Letters patent of the United States is: 
     
       1. An antigen for use in an assay for the presence of E. risticii antibodies, comprising the product prepared from the process comprising: (a) culturing human macrophage cells inoculated with E. risticii,   (b) harvesting, homogenizing and centrifuging cells suspended in a gradient, and   (c) isolating and recovering the centrifuged band having a density in said gradient of 1.8-1.9 g/ml.   
     
     
       2. The antigen of claim 1, wherein said human macrophage cells are human histiocyte lymphoma cells. 
     
     
       3. The antigen of claim 1, modified by the attachment of an enzyme thereto, for use in an enzyme-linked immunosorbent assay. 
     
     
       4. A kit for conducting an enzyme-linked immunosorbent assay, comprising the antigen of claim 1 in a sealed container.